Apparatus for dehydrating refrigerants



Filed March 22, 1955 INVENTOR AN/EL JORDAN NTTO R N E) APPARATUS FOR DEHYDRATIN G REFRlGER'ANTS Daniel Jordan, Pittsburgh, Pa.

Application March 22, 1955, Serial No. 495,991

1 Claim. (Cl. 62117.85)

This invention relates to an apparatus for dehydrating refrigerants as are employed in compressor-condenser evaporator refrigeration systems.

Important objects and advantages of the invention are to provide a dehydrating apparatus of the character described, which will increase the rate of absorption of the moisture in the refrigerant, which will increase the absorbent capacity of the desiccant and in consequence the capacities of the condenser and evaporator, which will function to remove dirt, scale and other extraneous matter from the refrigerant, and which allows the replacement of the desiccant when required.

Further objects of the invention are to provide an apparatus of the class described, which is simple in its con struction and arrangement, durable and efiicient in its use, compact, positive in its action, and comparatively economical in its manufacture, installation, operation and maintenance.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts herein specifically described and illustrated in the accompanying drawing, but it is to be understood that the latter is merely illustrative of an embodiment of the invention, and that changes in the form, proportions and details of construction may be resorted to that come within the scope of the claim hereunto appended.

In the drawing wherein like numerals of reference designate corresponding parts throughout the several views:

Figure 1 is a side elevational view, partly in section, of a dehydrating apparatus constructed in accordance with the invention.

Figure 2 is a transverse cross sectional view of the apparatus taken on line 2-2, Figure 1.

Figure 3 is a top plan view of the screen and of the filtering pad embodied in the present invention.

Figure 4 is a diagrammatic view of a refrigeration system incorporating the dehydrating apparatus of this invention.

Referring in detail to the drawing, Figure 4 illustrates a conventional compressor-ndenser-evaporator refrigeration system, which comprises a compressor 1 from the outlet of which the refrigerant is forced under pressure through a pipe 2 to a condenser 3. A discharge pipe 4 from the condenser connects with a receiver 5. Liquid pipes 6 and 6' connect the receiver with an expansion valve 7, and it is in these pipes 6 and 6' that the dehydrating apparatus 8, forming the invention, is located and connected. The expansion valve is connected with an evaporator 9 by a pipe 10, and a suction pipe 11 connects the evaporator with the inlet of the compressor. Another suction pipe 12 is connected with the dehydrating apparatus and is communicatively joined with the suction pipe 11.

The refrigerant dehydrating apparatus 8 is shown in detail in Figure 1, and comprises an inner cylindrical casing 13, which is enclosed by an outer cylindrical shell nited States Patent 0 14. The casing and shell are of uniform lengths and are concentrically arranged in spaced relation to each other to form a low pressure refrigerant chamber 15 therebetween.

A forward end head 16 and a rearward end head 17 have permanently fixed, leakproof connections with respective ends of the casing 13 and shell 14. The terms forward and rearward are herein applied relatively to the direction of flow of the refrigerant through the dehydrating apparatus 8. The end heads 16 and 17 are preferably though not necessarily tapered to form reduced outer ends.

The ends of the casing 13 open into respective end heads 16, 17, and the ends of the chamber 15 are completely closed and sealed by the connection of the end heads, as clearly illustrated in Figure 1.

The casing 13 is filled with a suitable desiccant 18 to remove the moisture from the fluid refrigerant passing therethrough. The desiccant can be in the form of silica gel, activated alumina, or any other suitable analogous absorbent material that best meets conditions found in practice.

A circular screen 19 and a suitable filtering disk 20, positioned rearwardly of and against the screen 19, are frictionally attached in the forward end of the casing 13 for filtering the refrigerant after passing through the desiccant 18 and for preventing the entrance of the latter into the forward end head 16.

A comparatively large hexagon-shaped collar 21, having a bore 22 formed with screw threads, is permanently secured against the reduced free end of the rearward end head 17. A tubular bushing 23, fixed to a nut 24 and projecting inwardly from the latter, is formed with exterior screw threads for removable engagement in the bore 22 of the collar 21. The bore 22 is of suflicient diameter size to allow the removal of the desiccant 18 therethrough from the casing 13 when the bushing is removed, and to allow the replacement of the desiccant when required.

The nut 21 carries a rearwardly projecting apertured nipple 24 which is formed with exterior screw threads for the engagement of a union nut 25 by which the liquid pipe 6 is detachably connected to the end head 17.

A thimble screen 26 is attached to the inner end of the bushing 23 and projects into the casing 13 to prevent the entrance of the desiccant 18 into the bushing bore 22 and thereby avert the possibility of impeding the flow of the refrigerant through the apertured nipple 24.

A hexagon-shaped collar 27 is permanently fixed against the reduced forward end of the end head 16, and a similarly shaped collar 28 is permanently fixed against the side of the shell 14 and is preferably located adjacent to the forward end of the latter.

The collar 27 carries a fixed, forwardly extending, apertured nipple 29, which is formed with exterior screw threads for the engagement of a union nut 30 thereon, whereby the liquid pipe 6' is detachably and communicatively joined with the apertured end head 16. In like manner, the collar 28 carries a fixed outwardly projecting, apertured nipple 31, which is formed with exterior screw threads for the engagement thereon of a union nut 32, whereby the suction pipe 12 is detachably and communicatively joined with the low pressure chamber 15 through the apertured wall of the shell 14, as clearly shown in Figure 1.

The purpose of providing the fixed collars 21, 27, and 28, with hexagon-shaped formations, is to allow a wrench or other holding implement to be engaged thereon to stabilize the dehydrating apparatus 8 while the latter is being joined with respective pipes 6, 6', and 12 during installation and removal operations in the refrigeration 3 system. It will be noted that the connections of the pipes 6, 6' and 12 With the dehydrating apparatus 8 is such that the latter can be readily removed and installed in the refrigeration system as and when required for any purpose.

A capillary tube 33 is suspended in the chamber 15 and preferably extends spirally around the casing 14. The inlet end portion of the tube extends through and has a leakproof connection in the forward end wall 34 of the chamber 15. The inlet end of the tube carries a screen 35 and is located in the end head 16 above the screen 19. The open outlet end 36 of the tube is located within the chamber 15.

The function of the capillary tube 33 is to meter a predetermined quantity of the filtered refrigerant, after the latter has been dehydrated by having passed through the desiccant 18, from the forward end of the dehydrating apparatus 8 into the chamber 15. The refrigerant conveyed through the tube into the chamber is under low pressure in the latter, and is drawn from the chamber by suction action through the suction pipe 12 to the suction pipe 11 without passing through the evaporator 9. This creates a circulatory flow of the refrigerant through they chamber 15 to thereby cause the chilling of the desiccant 18 to a degree whereby the absorbent capacity of the desiccant is greatly increased and maintained at maximum efficiency.

T he rate of the circulatory flow of the refrigerant through the chamber 15 is determined by the capacity of the capillary tube 33 and by the capacity and requirements of the refrigeration system and is such as to produce the optimum operating performance of the latter. The embodiment of the above-described desiccant chilling device in a conventional refrigeration system is the important feature of the present invention.

With the foregoing description taken in connection with the accompanying drawing, the construction and method of operation of the improved refrigerant dehydrating apparatus will be readily apparent to those skilled in the art to which the invention appertains, and it will be understood that the invention provides a most efficient device of its kind, which may be economically constructed and successfully employed for the purposes and in the manner herein set forth.

What I claim is:

A refrigerant dehydrating apparatus for a mechanical refrigeration system including a liquid line and a suction line comprising, in combination, an inner casing for containing the dehydrating material, an outer shell enclosing said casing and being arranged concentrically in spaced relation to the latter to provide a chamber between said casing and said shell, a forward end head and a rearward end head secured to respective ends of said casing and of said shell and providing sealing end walls for said chamber, an end screen covering the forward end of said casing, a filtering member mounted in said casing inwardly of said end screen, said forward end head having a detachable connection with the liquid line, a collar having a comparatively large bore fixed to the outer end of said rearward end head for allowing the removal and replacement of dehydrating material in said casing, a bushing having a detachable screw thread connection in said bore and with the liquid line, a screen carried at the inner end of said bushing and projecting into said casing, a capillary tube having open ends mounted in said chamber and being secured in said forward end head, the inlet end of said tube extending into said forward end head and carrying a screen, said tube conveying dehydrating refrigerant at a predetermined rate from said casing into said chamber, and a suction pipe communicatively connected with said chamber and with the suction line to draw the refrigerant from said chamber to create a constant flow of the refrigerant through said chamber to chill said dehydrating material for increasing the absorbent capacity of the latter.

Touborg Nov. 11, 1947 Wenk Dec. 11, 1951 

